E: Engine Hard starting.......due to cam timing.

[eglijim]

If the engine was any kind of modern 4 valve type, it would have bent all the valves.......At first i didn't realise the ignition was out 180 deg, Upon kicking it over, it actually did start and run, although the exhaust note was odd to say the least........The givaway was the bad kicking back on the kickstart lever........last time i found this was on a Shadow resto........with rebuilt mag, the camring housing was on 180 out and it was kicking back just the same........one thing to be careful of here.......if the ignition is out like that, the engine can actually backfire and catch fire. As this bike is kick start only.....can anyone tell me what, if any, kind of other type of folding kickstart will work on a Vincent spline......perhaps some type of Jap lever or similar.......this bike has rear sets, and the stock Vin lever digs into your shin........i've heated and bent the lever which is sort of acceptable, but still not the best........Probabaly take it for a test run today........Cheers.

There are a few Egli's sporting ( bottom) folding kickstart levers which are early Honda 750 but with the splines broached to fit the Vincent shaft. Bob Dunn had such a broach and I believe Mr Quirk has one too , mention it to Danny . Used Honda levers go for around £30 on Ebay over here , have also seen a few pics of cut and shut versions to get more leverage if there is enough ground clearance for the swing , still much cheaper than a genuine kickstart.

 

[Monkeypants]

I was actually very surprised with all the hard work Glen put into building that bike, that you didn't make it electric start.......I took this one for a run the other day.....went very well for a 1200 but the brakes were outstanding.........TZ Yamaha 260mm up front and smaller TZ single leader on the rear.......I recon you could put yourself over the bars with 2 fingers no trouble at all.........very impressive.

I didn't want the added weight of the e start. Also, it was doubtful that the Grosset starter would be strong enough.

Dag installed one on his 9 to 1 1200 TPV engine. Last I chatted with him it wasn't working.
I think the Grosset starters work very nicely on the standard bikes or even those with bumped cr but perhaps not on big bore squish head engines?

Glen

 

[greg brillus]

Hi there Glen, Yes I agree 100% big capacity engine is more than the Grosset starter system can handle........need to go to a system like the RTV had in the 90's........but it still has big issues that are difficult to overcome........Vincent S is going through that process now........very time consuming and experimental........I've yet to see a set up that works well all the time.......And these engines are far from high spec when it comes to capacity and performance really.

 

[Bill Thomas]

On Our Forum photos today,
A short one from a Yamaha 750 on a Burman Kickstart.

 

[greg brillus]

Thanks Bill.......I've bent this one so it just clears the right shin whilst on the bike.........wouldn't be good in a head on prang, but anyway it should be fine........If the owner complains about it, i'll sort something similar to the pics shown, as there doesn't seem to be anything readily available which is to be expected on such a limited bike........cheers.

 

[Bill Thomas]

Sometimes it's nice to go back to Standard ,
Less Stress ?, Must be getting Old !.

 

[stu spalding]

Yes I agree 100% big capacity engine is more than the Grosset starter system can handle.

Hi Greg, Herve Hamon made a batch of motors that were a straight swap for the Grosset motor, and a bit beefier too. Mine's based on a Toyota Celica starter. I'm not sure of availability but I have seen others. Cheers, Stu.

 

[Monkeypants]

....And these engines are far from high spec when it comes to capacity and performance really.

They do very well in their rpm design range which is up to 7,000 rpm with Terry Prince components and new strengthened crankcase.

I compared the dyno results from the recent 1330 TP engine build to modern dyno charts. On a power output per cc basis, I couldn't find anything that equals the output of these engines in that rpm range.
The sportbike output to 7 k isn't even close, either on a per cc measure or overall. Most are very anemic in this range. They more than make up for it with very high rpm, but not all of us enjoy that type of engine or ride.
The only engine that came close to the TP engine on a power per cc basis to 7 k was the Triumph Thruxton r 1200. It operates in roughly the same rpm range and makes tremendous torque from 2500 rpm on, as does the Prince engine. The Thruxton 1200 will do zero to sixty in 3 seconds, and a top gear roll on from 60-80 mph also in 3 seconds, which is quicker than most litre sportbikes. Litre sportbikes lack torque at that rpm.

The Prince engine with the Egli cams makes slightly more overall power per cc than the Triumph.
I think this is quite remarkable as the Triumph uses all the modern tricks, 4 valves per cylinder, water cooling and ride by wire computer controlled electronic fuel injection and ignition.
You would expect it to outdo an ancient design, air cooled, carbueretted, pushrod engine by a mile.

Glen

 

[DucATIRadeon]

Been busy carrying out some work on an Egli with genuine Shadow engine........primarily set up as a race bike methinks, but has lights and horn.......Had a pair of 38 mm Gardeners.........1200 cc TPV heads/barrels.......Tri spark twin plug ignition. Ignition was out 180 degrees so there was my starting point........Gardeners too difficult to tune for a road engine.......removed and installed a new set of pumper 40 mm Dellortos' and made up some manifolds to suit.......Great all looking good so far.......Engine would run actually quite well, but very difficult to start.......tried different starting techniques but nothing really jumping out to make it better........It did have an oil leak at the timing cover........I suspected that it might have some big cams that were making the starting an issue....... removed the cover, naturally 2 of the spindles were loose and no seal at all on the valve lifter mech.......At this point I noticed the cam locating slots were out on both cams by 3 teeth retarded.........Hmmmm........Fixed all within the chest, re set the cams to bring the slots in line with the barrel centers........re set the ignition to 28 full advance, reassembled all parts and timing cover.......filled the oil tank with 15 w 40 oil, bled the feed line........plugs and caps on, fuel on opened the throttle fully twice, started 1st kick.........Love to know who was the last person to work on this bike........The reason I felt the engine may have had big cams in it was........when it was running before i removed the cover, it had quite a lot of reversion visual from the front carby........the cams were just Mk 2 Lightning cams so nothing crazy there........just retarded by 45 degrees.......So nice to be able to give the bike back to the owner knowing it will start ok and not be a total pig........Sometimes you have to look further than you think especially if the bike has an unknown or unusual history........I can give my right leg a break now..........Cheers.

had similar symptoms/problem with my C rapide on first starting attempt.
bikes been sitting for the better part of 30 years with the usual crud settling down everywhere. cleaned all up, temporarily replaced oil lines (scavange line to heads literally snapped in half!) with 8mm fuel lines and clamps, fresh oil and give it a go.

I think it was a good move to have the windows replaced with double glazing, as the amount of backfire and banging from the exhaust would've clearly blown the windows out... I had ringing ears for the better part of the evening, blimey!

anyway: it was a terribly hard to start it and it only ran on the front cilinder, and a pissed-off dragon breathing out the rear carb (with the frequent banging in the pipe). this being my first old big twin it sure did test my stamina incl valve lifter (I come from less older Ducati bevel background and Royal Enfield).
it occurred to me that whilst priming I could clearly hear the front suck air, but the rear was sucking AND blowing. that's when I thought hang on, is that reversion?
so popped the thing chest and sure enough: the rear cam was retarded 2 teeth and the from advanced 1 tooth. bike mechanical history 101% unknown. using the data in the literature the single dot on the rear cam should be 159degrees clockwise from the slot, compared to the actual gear mesh showed the 2 teeth retard and 1 tooth advance, without even measuring valve lift whatever.

got the lot sorted as good as I could get it, without pressing out the cams from the gears, shifting the half-time pinion about, ignoring the marks on the cams (they're off-spec too!) this time using a degree wheel and dial gauge for the 0.13mm/0.005" valve lift) it starts easier and runs much smoother than before (but still bootcamp stamina starting), no fire-breathing dragons, only bangs now and then when restarting on a hot engine. full advance is set 38degrees BTDC rear cylinder as per instructions.
current nicks are leaking rear koni damper (Special "D" 76C 1083?), oil oozing from the ratchet shaft bearing, oil thrown out form the dynamo boss and rather lean combustions from the AMAL 389/689 1-5/32" with 250 mains.
stock 998 with (I assume) 7:1, Mk1 cams (I'm told based on pics), 21/46 gearing, 19" front 18" rear, and as a bonus the aluminium BS brake plates up front (with integrated into casting air scoops, not screwed on scoops!)

sorry to hi-jack your thread, got carried away there.
the essence is: I had cams out-of-spec few teeth with backfire/reversion.
putting them back to close as possible timing made a world of difference.

 

[Bill Thomas]

I thought you was going to say you timed the ignition 180 degrees out,
Like I did !,
Ashamed to say all my fault,
It was an old engine been laid up for 40 plus years and I filled everything with oil,
So I thought it would be hard to start,
Just before I had a go, I slipped the end plate off the old Mag' to take a shim out,
And put it back wrong,
Just very tired and a little OLD !,
But I didn't give up for a LONG while, Kicked my heart out !.
Until called in for dinner, Soon as my head hit the pillow I knew, Bugger,
Next morning I fitted a garden glove inside my boot,
To ease a very damaged foot.
After all my years as a mechanic , Felt very SILLY.